Automatic Proxy URL

Hello everyone.

Apologies if this has been answered elsewher - but I've spent a while searching on whatever relevant keywords i can think of - and have drawn a blank.

With the demise of Meebo, I am trying to find a portable IM client that I can use at my workplace.

The problem is, that my work uses an .pac to set the proxy. I can get to and read this file, but I'm unable to determine the settings to use in a proxy config dialog in the IM client.

I have tried using the URL I think (I may be wrong of course) is the correct proxy - I've tried it as a n http and socks 5 proxy, with or without the username & password (I don't need one for browsing at the office - I think it probably uses my domain credentials)

One or two of the clients have a "use environment" setting - I don't know how to set this up - and probably can't - no admin rights.

If anyone can suggest either a way to resolve this - a way to determine the actual proxy in use (there are literally hundreds - it's a big worldwide company)

I have tried eBuddy - it's a POS - not working reliably. most other chat sites have been "webpoliced" so can't be used.

I have Yoono working - but it doesn't "do" MSN as far as I can see. And it seems to keep dropping out & having to log back in.

I need to have cross platform - Gtalk, MSN/Live, Yahoo, Facebook.

Thanks